<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background: #f8fafc;
      color: #1e293b;
      padding: 10px;
      display: flex;
      flex-direction: column;
      gap: 8px;
      user-select: none;
    }

    .controls {
      display: flex;
      justify-content: center;
      gap: 6px;
      flex-wrap: wrap;
    }

    .btn {
      padding: 5px 12px;
      font-size: 12px;
      font-weight: 600;
      border: 1px solid #cbd5e1;
      border-radius: 20px;
      background: #ffffff;
      color: #475569;
      cursor: pointer;
      transition: background 0.2s, color 0.2s, box-shadow 0.2s;
    }

    .btn.active {
      background: #0284c7;
      color: #ffffff;
      border-color: #0284c7;
      box-shadow: 0 2px 6px rgba(2, 132, 199, 0.3);
    }

    .panels-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 8px;
      width: 100%;
    }

    @media (max-width: 480px) {
      .panels-grid {
        grid-template-columns: 1fr;
      }
    }

    .env-panel {
      background: #ffffff;
      border-radius: 12px;
      border: 1px solid #e2e8f0;
      padding: 10px;
      display: flex;
      flex-direction: column;
      gap: 8px;
      position: relative;
      overflow: hidden;
      transition: opacity 0.3s;
    }

    .env-title {
      font-size: 13px;
      font-weight: 700;
      letter-spacing: 0.5px;
      text-transform: uppercase;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .terrestrial-title { color: #15803d; }
    .aquatic-title { color: #0369a1; }

    .interaction-card {
      background: #f8fafc;
      border-radius: 8px;
      border: 1px solid #f1f5f9;
      padding: 8px;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 6px;
      position: relative;
      transition: background 0.3s, border-color 0.3s, box-shadow 0.3s;
    }

    .interaction-card.highlight {
      background: #ffffff;
      border-color: #38bdf8;
      box-shadow: 0 0 0 2px rgba(56, 189, 248, 0.4);
    }

    .abiotic-node, .biotic-node {
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      min-width: 60px;
    }

    .icon-box {
      font-size: 24px;
      line-height: 1;
      height: 30px;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .node-tag {
      font-size: 10px;
      font-weight: 700;
      color: #64748b;
      margin-top: 2px;
      text-transform: uppercase;
    }

    .flow-connector {
      flex: 1;
      display: flex;
      flex-direction: column;
      align-items: center;
      padding: 0 4px;
    }

    .effect-pill {
      font-size: 11px;
      font-weight: 600;
      color: #0f172a;
      background: #e2e8f0;
      padding: 3px 6px;
      border-radius: 4px;
      text-align: center;
      line-height: 1.2;
      white-space: nowrap;
      margin-bottom: 3px;
      transition: background 0.3s, color 0.3s;
    }

    .interaction-card.highlight .effect-pill {
      background: #0284c7;
      color: #ffffff;
    }

    .arrow-svg {
      width: 100%;
      height: 12px;
      display: block;
    }

    .dimmed {
      opacity: 0.35;
    }
  </style>
</head>
<body>

  <div class="controls">
    <button class="btn active" id="btn-all" onclick="setFilter('all')">All Direct Links</button>
    <button class="btn" id="btn-terr" onclick="setFilter('terr')">Terrestrial</button>
    <button class="btn" id="btn-aqua" onclick="setFilter('aqua')">Aquatic</button>
  </div>

  <div class="panels-grid">
    
    <div class="env-panel" id="panel-terr">
      <div class="env-title terrestrial-title">
        <span>🌱</span> Terrestrial Environment
      </div>

      
      <div class="interaction-card highlight" id="card-sun">
        <div class="abiotic-node">
          <div class="icon-box">☀️</div>
          <div class="node-tag">Sunlight</div>
        </div>
        <div class="flow-connector">
          <div class="effect-pill">Powers Photosynthesis</div>
          <svg class="arrow-svg" viewBox="0 0 80 12" preserveAspectRatio="none">
            <line x1="0" y1="6" x2="70" y2="6" stroke="#eab308" stroke-width="2.5" stroke-dasharray="4 2" />
            <polygon points="70,2 78,6 70,10" fill="#eab308" />
          </svg>
        </div>
        <div class="biotic-node">
          <div class="icon-box">🌿</div>
          <div class="node-tag">Plant</div>
        </div>
      </div>

      
      <div class="interaction-card highlight" id="card-rain">
        <div class="abiotic-node">
          <div class="icon-box">🌧️</div>
          <div class="node-tag">Moisture</div>
        </div>
        <div class="flow-connector">
          <div class="effect-pill">Root Absorption</div>
          <svg class="arrow-svg" viewBox="0 0 80 12" preserveAspectRatio="none">
            <line x1="0" y1="6" x2="70" y2="6" stroke="#3b82f6" stroke-width="2.5" stroke-dasharray="4 2" />
            <polygon points="70,2 78,6 70,10" fill="#3b82f6" />
          </svg>
        </div>
        <div class="biotic-node">
          <div class="icon-box">🪴</div>
          <div class="node-tag">Roots</div>
        </div>
      </div>
    </div>

    
    <div class="env-panel" id="panel-aqua">
      <div class="env-title aquatic-title">
        <span>🌊</span> Aquatic Environment
      </div>

      
      <div class="interaction-card highlight" id="card-o2">
        <div class="abiotic-node">
          <div class="icon-box">🫧</div>
          <div class="node-tag">Dissolved O₂</div>
        </div>
        <div class="flow-connector">
          <div class="effect-pill">Enters Gills</div>
          <svg class="arrow-svg" viewBox="0 0 80 12" preserveAspectRatio="none">
            <line x1="0" y1="6" x2="70" y2="6" stroke="#0284c7" stroke-width="2.5" stroke-dasharray="4 2" />
            <polygon points="70,2 78,6 70,10" fill="#0284c7" />
          </svg>
        </div>
        <div class="biotic-node">
          <div class="icon-box">🐟</div>
          <div class="node-tag">Trout</div>
        </div>
      </div>

      
      <div class="interaction-card highlight" id="card-temp">
        <div class="abiotic-node">
          <div class="icon-box">🌡️</div>
          <div class="node-tag">Water Temp</div>
        </div>
        <div class="flow-connector">
          <div class="effect-pill">Sets Metabolic Rate</div>
          <svg class="arrow-svg" viewBox="0 0 80 12" preserveAspectRatio="none">
            <line x1="0" y1="6" x2="70" y2="6" stroke="#ef4444" stroke-width="2.5" stroke-dasharray="4 2" />
            <polygon points="70,2 78,6 70,10" fill="#ef4444" />
          </svg>
        </div>
        <div class="biotic-node">
          <div class="icon-box">⚡</div>
          <div class="node-tag">Metabolism</div>
        </div>
      </div>
    </div>
  </div>

  <script>
    function setFilter(mode) {
      document.querySelectorAll('.btn').forEach(b => b.classList.remove('active'));
      const terrPanel = document.getElementById('panel-terr');
      const aquaPanel = document.getElementById('panel-aqua');

      if (mode === 'all') {
        document.getElementById('btn-all').classList.add('active');
        terrPanel.classList.remove('dimmed');
        aquaPanel.classList.remove('dimmed');
      } else if (mode === 'terr') {
        document.getElementById('btn-terr').classList.add('active');
        terrPanel.classList.remove('dimmed');
        aquaPanel.classList.add('dimmed');
      } else if (mode === 'aqua') {
        document.getElementById('btn-aqua').classList.add('active');
        terrPanel.classList.add('dimmed');
        aquaPanel.classList.remove('dimmed');
      }
    }
  </script>
</body>
</html>

Living and Nonliving Components of Ecosystems

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background: transparent;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      height: 100%;
      min-height: 420px;
      user-select: none;
      padding: 10px;
      gap: 8px;
    }

    /* Top Controls / Stepper */
    .controls-bar {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 6px;
      flex-wrap: wrap;
    }
    .stepper-tabs {
      display: flex;
      gap: 6px;
      flex: 1;
      min-width: 260px;
    }
    .step-pill {
      flex: 1;
      background: #f1f5f9;
      border: 1.5px solid #e2e8f0;
      border-radius: 20px;
      padding: 6px 4px;
      font-size: 12px;
      font-weight: 600;
      text-align: center;
      cursor: pointer;
      color: #64748b;
      transition: all 0.25s ease;
      white-space: nowrap;
    }
    .step-pill.active {
      background: #e0f2fe;
      border-color: #0284c7;
      color: #0369a1;
      box-shadow: 0 1px 4px rgba(2, 132, 199, 0.15);
    }
    .playback-btns {
      display: flex;
      gap: 4px;
    }
    .btn-ctrl {
      background: #ffffff;
      border: 1.5px solid #cbd5e1;
      border-radius: 6px;
      padding: 5px 10px;
      font-size: 13px;
      font-weight: 600;
      cursor: pointer;
      color: #334155;
      display: flex;
      align-items: center;
      justify-content: center;
      transition: background 0.2s;
    }
    .btn-ctrl:active { background: #f1f5f9; }

    /* Lake Cutaway Canvas Area */
    .stage-container {
      position: relative;
      flex: 1;
      min-height: 220px;
      border-radius: 12px;
      overflow: hidden;
      border: 1px solid #cbd5e1;
      background: #e0f2fe;
    }

    svg.lake-svg {
      width: 100%;
      height: 100%;
      display: block;
    }

    /* Water background transition */
    #water-rect {
      transition: fill 0.6s ease;
    }

    /* Sunlight Rays */
    #sunlight {
      transition: opacity 0.5s ease;
    }

    /* Algae Surface Layer */
    #algae-layer {
      transition: transform 0.6s ease, opacity 0.5s ease;
      transform-origin: top center;
    }

    /* Sinking Debris & Microbes */
    #decomposers, #sinking-matter {
      transition: opacity 0.5s ease;
    }

    /* Fish animations */
    .fish-group {
      transition: transform 0.6s ease, opacity 0.5s ease;
    }

    /* O2 Gauge in SVG / Overlay */
    .gauge-card {
      position: absolute;
      top: 10px;
      right: 10px;
      background: rgba(255, 255, 255, 0.94);
      border: 1px solid #cbd5e1;
      border-radius: 8px;
      padding: 6px 10px;
      display: flex;
      align-items: center;
      gap: 8px;
      box-shadow: 0 2px 6px rgba(0,0,0,0.06);
    }
    .gauge-ring {
      width: 32px;
      height: 32px;
      border-radius: 50%;
      border: 4px solid #e2e8f0;
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 11px;
      font-weight: 700;
      transition: border-color 0.5s ease, color 0.5s ease;
    }
    .gauge-label {
      display: flex;
      flex-direction: column;
    }
    .gauge-title {
      font-size: 10px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.5px;
      color: #64748b;
    }
    .gauge-val {
      font-size: 13px;
      font-weight: 700;
    }

    /* Key dynamic particles */
    .nutrient-dot {
      animation: driftDown 3s infinite linear;
    }
    @keyframes driftDown {
      0% { transform: translateY(0) translateX(0); opacity: 1; }
      100% { transform: translateY(50px) translateX(20px); opacity: 0.2; }
    }

    /* Bottom Info Banner */
    .info-panel {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 10px;
      padding: 8px 12px;
      display: flex;
      flex-direction: column;
      gap: 5px;
    }
    .info-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 8px;
      flex-wrap: wrap;
    }
    .step-title {
      font-size: 14px;
      font-weight: 700;
      color: #0f172a;
    }
    .badges-row {
      display: flex;
      gap: 6px;
      flex-wrap: wrap;
    }
    .badge {
      font-size: 11px;
      font-weight: 600;
      padding: 2px 8px;
      border-radius: 12px;
      display: inline-flex;
      align-items: center;
      gap: 4px;
    }
    .badge-abiotic {
      background: #fef3c7;
      color: #b45309;
      border: 1px solid #fde68a;
    }
    .badge-biotic {
      background: #dcfce7;
      color: #15803d;
      border: 1px solid #bbf7d0;
    }
    .info-desc {
      font-size: 12px;
      color: #475569;
      line-height: 1.35;
    }
  </style>
</head>
<body>

  
  <div class="controls-bar">
    <div class="stepper-tabs">
      <button class="step-pill active" onclick="setStep(0)">1. Nutrient Influx</button>
      <button class="step-pill" onclick="setStep(1)">2. Algae Bloom</button>
      <button class="step-pill" onclick="setStep(2)">3. O₂ Depletion</button>
      <button class="step-pill" onclick="setStep(3)">4. Dead Zone</button>
    </div>
    <div class="playback-btns">
      <button class="btn-ctrl" onclick="prevStep()">◀</button>
      <button class="btn-ctrl" id="playBtn" onclick="togglePlay()">⏸</button>
      <button class="btn-ctrl" onclick="nextStep()">▶</button>
    </div>
  </div>

  
  <div class="stage-container">
    <svg class="lake-svg" viewBox="0 0 600 320" preserveAspectRatio="none">
      <defs>
        
        <linearGradient id="sunGrad" x1="0%" y1="0%" x2="0%" y2="100%">
          <stop offset="0%" stop-color="#fef08a" stop-opacity="0.45" />
          <stop offset="100%" stop-color="#fef08a" stop-opacity="0" />
        </linearGradient>
        <linearGradient id="bankGrad" x1="0%" y1="0%" x2="100%" y2="100%">
          <stop offset="0%" stop-color="#65a30d" />
          <stop offset="100%" stop-color="#4d7c0f" />
        </linearGradient>
        <linearGradient id="bedGrad" x1="0%" y1="0%" x2="0%" y2="100%">
          <stop offset="0%" stop-color="#78716c" />
          <stop offset="100%" stop-color="#44403c" />
        </linearGradient>
      </defs>

      
      <rect x="0" y="0" width="600" height="70" fill="#bae6fd" />
      <circle cx="480" cy="35" r="22" fill="#fde047" opacity="0.9" />

      
      <polygon points="0,40 140,70 110,130 0,160" fill="url(#bankGrad)" />
      <path d="M 10 50 L 50 48 M 60 55 L 100 52 M 20 65 L 80 62" stroke="#a3e635" stroke-width="3" stroke-linecap="round" />
      <text x="12" y="32" font-size="11" font-weight="700" fill="#365314">Agricultural Runoff</text>

      
      <rect id="water-rect" x="0" y="70" width="600" height="210" fill="#38bdf8" />

      
      <polygon points="0,280 600,280 600,320 0,320" fill="url(#bedGrad)" />

      
      <g id="sunlight" opacity="1">
        <polygon points="460,50 320,280 580,280 500,50" fill="url(#sunGrad)" />
        <polygon points="300,60 160,280 400,280 340,60" fill="url(#sunGrad)" />
      </g>

      
      <g id="nutrient-flow" opacity="1" transition="opacity 0.4s">
        <path d="M 100 70 Q 140 90 180 120" stroke="#f59e0b" stroke-dasharray="4,4" stroke-width="3" fill="none" />
        
        <circle cx="120" cy="85" r="5" fill="#f59e0b" />
        <text x="117" y="88" font-size="8" font-weight="800" fill="#fff">N</text>
        <circle cx="145" cy="100" r="5" fill="#eab308" />
        <text x="142" y="103" font-size="8" font-weight="800" fill="#fff">P</text>
        <circle cx="170" cy="115" r="5" fill="#f59e0b" />
        <text x="167" y="118" font-size="8" font-weight="800" fill="#fff">N</text>
        <circle cx="135" cy="130" r="4" fill="#eab308" />
        <circle cx="190" cy="140" r="4" fill="#f59e0b" />
      </g>

      
      <g id="algae-layer" opacity="0" transform="scale(1, 0.2)">
        <rect x="0" y="70" width="600" height="24" fill="#16a34a" opacity="0.9" />
        
        <ellipse cx="60" cy="82" rx="35" ry="8" fill="#15803d" />
        <ellipse cx="150" cy="84" rx="45" ry="9" fill="#22c55e" />
        <ellipse cx="260" cy="82" rx="55" ry="10" fill="#15803d" />
        <ellipse cx="380" cy="85" rx="50" ry="9" fill="#166534" />
        <ellipse cx="490" cy="83" rx="60" ry="10" fill="#22c55e" />
        <ellipse cx="570" cy="84" rx="35" ry="8" fill="#15803d" />
        <text x="230" y="86" font-size="12" font-weight="800" fill="#ffffff" letter-spacing="1">DENSE ALGAL BLOOM</text>
      </g>

      
      <g id="sinking-matter" opacity="0">
        
        <circle cx="210" cy="160" r="4" fill="#166534" opacity="0.7" />
        <circle cx="280" cy="190" r="5" fill="#3f6212" opacity="0.8" />
        <circle cx="370" cy="170" r="4" fill="#166534" opacity="0.7" />
        <circle cx="430" cy="210" r="6" fill="#3f6212" opacity="0.8" />
        <circle cx="180" cy="220" r="5" fill="#1e3a1e" opacity="0.8" />
        
        <line x1="210" y1="120" x2="210" y2="155" stroke="#166534" stroke-dasharray="2,3" stroke-width="1.5" />
        <line x1="280" y1="120" x2="280" y2="185" stroke="#166534" stroke-dasharray="2,3" stroke-width="1.5" />
        <line x1="370" y1="120" x2="370" y2="165" stroke="#166534" stroke-dasharray="2,3" stroke-width="1.5" />
        <line x1="430" y1="120" x2="430" y2="205" stroke="#166534" stroke-dasharray="2,3" stroke-width="1.5" />
      </g>

      
      <g id="decomposers" opacity="0">
        
        <circle cx="200" cy="272" r="7" fill="#a855f7" opacity="0.8" />
        <circle cx="212" cy="274" r="5" fill="#9333ea" opacity="0.8" />
        <circle cx="290" cy="270" r="8" fill="#a855f7" opacity="0.85" />
        <circle cx="302" cy="273" r="6" fill="#c084fc" opacity="0.85" />
        <circle cx="380" cy="272" r="9" fill="#9333ea" opacity="0.9" />
        <circle cx="395" cy="275" r="7" fill="#a855f7" opacity="0.85" />
        <circle cx="480" cy="271" r="8" fill="#9333ea" opacity="0.9" />
        <text x="270" y="260" font-size="10" font-weight="700" fill="#fae8ff">Bacteria Multiplying (Consuming O₂)</text>
      </g>

      
      
      <g id="fish-1" class="fish-group" transform="translate(240, 180)">
        <ellipse cx="0" cy="0" rx="14" ry="7" fill="#f97316" />
        <polygon points="12,0 20,-6 20,6" fill="#ea580c" />
        <circle cx="-7" cy="-2" r="1.5" fill="#000" />
      </g>
      <g id="fish-2" class="fish-group" transform="translate(380, 210)">
        <ellipse cx="0" cy="0" rx="16" ry="8" fill="#38bdf8" />
        <polygon points="14,0 23,-7 23,7" fill="#0284c7" />
        <circle cx="-8" cy="-2" r="1.5" fill="#000" />
      </g>
      <g id="fish-3" class="fish-group" transform="translate(460, 150)">
        <ellipse cx="0" cy="0" rx="12" ry="6" fill="#f59e0b" />
        <polygon points="10,0 17,-5 17,5" fill="#d97706" />
        <circle cx="-6" cy="-2" r="1.2" fill="#000" />
      </g>

      
      <path d="M 60 280 Q 55 230 70 210 Q 80 235 75 280" fill="#22c55e" id="plant-1" />
      <path d="M 80 280 Q 95 240 85 220 Q 75 245 90 280" fill="#16a34a" id="plant-2" />

    </svg>

    
    <div class="gauge-card">
      <div class="gauge-ring" id="gaugeRing">95%</div>
      <div class="gauge-label">
        <span class="gauge-title">Dissolved O₂</span>
        <span class="gauge-val" id="gaugeVal" style="color: #0284c7;">Healthy</span>
      </div>
    </div>
  </div>

  
  <div class="info-panel">
    <div class="info-header">
      <div class="step-title" id="stepTitle">Step 1: Nutrient Influx (Runoff)</div>
      <div class="badges-row">
        <span class="badge badge-abiotic" id="abioticBadge">Abiotic: High N & P Fertilizer</span>
        <span class="badge badge-biotic" id="bioticBadge">Biotic: Normal Food Web</span>
      </div>
    </div>
    <div class="info-desc" id="stepDesc">
      Abiotic chemical nutrients (nitrogen and phosphorus) wash into clear lake water, triggering rapid ecological changes.
    </div>
  </div>

  <script>
    const stepData = [
      {
        title: "1. Nutrient Influx (Runoff)",
        abiotic: "Abiotic: Excess N & P Runoff",
        biotic: "Biotic: Healthy Native Ecosystem",
        desc: "Abiotic fertilizers run off agricultural land into the lake, supercharging the aquatic environment with excess nitrogen and phosphorus.",
        waterColor: "#38bdf8",
        sunlightOpacity: "1",
        nutrientsOpacity: "1",
        algaeOpacity: "0",
        algaeScale: "scale(1, 0.1)",
        sinkingOpacity: "0",
        decomposerOpacity: "0",
        plantFill: "#22c55e",
        o2Percent: "95%",
        o2Status: "Optimal",
        o2Color: "#0284c7",
        gaugeBorder: "#38bdf8",
        fish1: "translate(240, 180) rotate(0)",
        fish2: "translate(380, 210) rotate(0)",
        fish3: "translate(460, 150) rotate(0)",
        fishOpacity: "1"
      },
      {
        title: "2. Biotic Explosion (Algal Bloom)",
        abiotic: "Abiotic: Sunlight Blocked Below",
        biotic: "Biotic: Rapid Algae Overgrowth",
        desc: "Fed by surplus nutrients, biotic algae multiplies exponentially across the surface, blocking essential abiotic sunlight from submerged plants.",
        waterColor: "#67e8f9",
        sunlightOpacity: "0.25",
        nutrientsOpacity: "0.3",
        algaeOpacity: "0.95",
        algaeScale: "scale(1, 1)",
        sinkingOpacity: "0.2",
        decomposerOpacity: "0.2",
        plantFill: "#65a30d",
        o2Percent: "70%",
        o2Status: "Declining",
        o2Color: "#0284c7",
        gaugeBorder: "#38bdf8",
        fish1: "translate(240, 190) rotate(5)",
        fish2: "translate(370, 220) rotate(-4)",
        fish3: "translate(450, 170) rotate(3)",
        fishOpacity: "1"
      },
      {
        title: "3. Bacterial Decomposition & O₂ Drain",
        abiotic: "Abiotic: Rapid Oxygen Depletion",
        biotic: "Biotic: Microbes Decompose Biomass",
        desc: "Algae dies and sinks. Billions of biotic decomposer bacteria consume massive amounts of abiotic dissolved oxygen while breaking down dead matter.",
        waterColor: "#475569",
        sunlightOpacity: "0.1",
        nutrientsOpacity: "0",
        algaeOpacity: "0.7",
        algaeScale: "scale(1, 0.8)",
        sinkingOpacity: "1",
        decomposerOpacity: "1",
        plantFill: "#475569",
        o2Percent: "25%",
        o2Status: "Hypoxic",
        o2Color: "#f59e0b",
        gaugeBorder: "#f59e0b",
        fish1: "translate(230, 170) rotate(-25)",
        fish2: "translate(360, 230) rotate(-35)",
        fish3: "translate(440, 190) rotate(-30)",
        fishOpacity: "0.8"
      },
      {
        title: "4. Dead Zone (Hypoxia & Die-Off)",
        abiotic: "Abiotic: Anoxic / Depleted O₂",
        biotic: "Biotic: Fish Die-Off & Loss of Life",
        desc: "With dissolved oxygen nearly zero, fish and larger aquatic organisms suffocate, creating a biological dead zone devoid of animal life.",
        waterColor: "#334155",
        sunlightOpacity: "0.05",
        nutrientsOpacity: "0",
        algaeOpacity: "0.4",
        algaeScale: "scale(1, 0.6)",
        sinkingOpacity: "0.5",
        decomposerOpacity: "0.9",
        plantFill: "#334155",
        o2Percent: "3%",
        o2Status: "Dead Zone",
        o2Color: "#ef4444",
        gaugeBorder: "#ef4444",
        fish1: "translate(220, 85) rotate(180)",
        fish2: "translate(350, 95) rotate(180)",
        fish3: "translate(430, 90) rotate(180)",
        fishOpacity: "0.45"
      }
    ];

    let currentStep = 0;
    let timer = null;
    let isPlaying = true;

    function renderStep(idx) {
      const data = stepData[idx];

      // Update Stepper Pills
      document.querySelectorAll('.step-pill').forEach((pill, i) => {
        pill.classList.toggle('active', i === idx);
      });

      // Update Lake Graphics
      document.getElementById('water-rect').setAttribute('fill', data.waterColor);
      document.getElementById('sunlight').style.opacity = data.sunlightOpacity;
      document.getElementById('nutrient-flow').style.opacity = data.nutrientsOpacity;
      
      const algae = document.getElementById('algae-layer');
      algae.style.opacity = data.algaeOpacity;
      algae.setAttribute('transform', data.algaeScale);

      document.getElementById('sinking-matter').style.opacity = data.sinkingOpacity;
      document.getElementById('decomposers').style.opacity = data.decomposerOpacity;
      
      document.getElementById('plant-1').setAttribute('fill', data.plantFill);
      document.getElementById('plant-2').setAttribute('fill', data.plantFill);

      // Fish Positions/Rotations
      const f1 = document.getElementById('fish-1');
      const f2 = document.getElementById('fish-2');
      const f3 = document.getElementById('fish-3');
      f1.setAttribute('transform', data.fish1);
      f2.setAttribute('transform', data.fish2);
      f3.setAttribute('transform', data.fish3);
      f1.style.opacity = data.fishOpacity;
      f2.style.opacity = data.fishOpacity;
      f3.style.opacity = data.fishOpacity;

      // Update Gauge
      const ring = document.getElementById('gaugeRing');
      const val = document.getElementById('gaugeVal');
      ring.textContent = data.o2Percent;
      ring.style.borderColor = data.gaugeBorder;
      ring.style.color = data.o2Color;
      val.textContent = data.o2Status;
      val.style.color = data.o2Color;

      // Update Banner Text
      document.getElementById('stepTitle').textContent = data.title;
      document.getElementById('abioticBadge').textContent = data.abiotic;
      document.getElementById('bioticBadge').textContent = data.biotic;
      document.getElementById('stepDesc').textContent = data.desc;
    }

    function setStep(idx) {
      currentStep = idx;
      renderStep(currentStep);
    }

    function nextStep() {
      currentStep = (currentStep + 1) % stepData.length;
      renderStep(currentStep);
    }

    function prevStep() {
      currentStep = (currentStep - 1 + stepData.length) % stepData.length;
      renderStep(currentStep);
    }

    function togglePlay() {
      isPlaying = !isPlaying;
      document.getElementById('playBtn').textContent = isPlaying ? '⏸' : '▶';
      if (isPlaying) {
        startTimer();
      } else {
        clearInterval(timer);
      }
    }

    function startTimer() {
      clearInterval(timer);
      timer = setInterval(() => {
        if (isPlaying) nextStep();
      }, 4000);
    }

    // Initialize
    renderStep(0);
    startTimer();
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
      background: #f8fafc;
      color: #1e293b;
      padding: 12px;
      display: flex;
      flex-direction: column;
      gap: 10px;
      min-height: 100%;
    }

    .header-bar {
      display: flex;
      justify-content: space-between;
      align-items: center;
      flex-wrap: wrap;
      gap: 8px;
    }

    .main-title {
      font-size: 16px;
      font-weight: 700;
      color: #0f172a;
      letter-spacing: -0.01em;
    }

    .filter-group {
      display: flex;
      gap: 4px;
      background: #e2e8f0;
      padding: 2px;
      border-radius: 8px;
    }

    .filter-btn {
      border: none;
      background: transparent;
      padding: 4px 10px;
      font-size: 12px;
      font-weight: 600;
      color: #64748b;
      border-radius: 6px;
      cursor: pointer;
      transition: background 0.2s, color 0.2s;
    }

    .filter-btn.active {
      background: #ffffff;
      color: #0f172a;
      box-shadow: 0 1px 2px rgba(0, 0, 0, 0.08);
    }

    .columns-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 10px;
      flex: 1;
    }

    @media (max-width: 420px) {
      .columns-grid {
        grid-template-columns: 1fr;
      }
    }

    .column-card {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 10px;
      display: flex;
      flex-direction: column;
      gap: 8px;
      transition: opacity 0.25s ease;
    }

    .column-card.dimmed {
      opacity: 0.25;
    }

    .badge-header {
      padding: 6px 10px;
      border-radius: 8px;
      font-size: 13px;
      font-weight: 700;
      text-align: center;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
    }

    .biotic-badge {
      background: #dcfce7;
      color: #15803d;
      border: 1px solid #bbf7d0;
    }

    .abiotic-badge {
      background: #e0f2fe;
      color: #0369a1;
      border: 1px solid #bae6fd;
    }

    .items-list {
      display: flex;
      flex-direction: column;
      gap: 6px;
    }

    .factor-item {
      display: flex;
      align-items: center;
      gap: 10px;
      padding: 7px 10px;
      background: #f8fafc;
      border: 1px solid #f1f5f9;
      border-radius: 8px;
      cursor: pointer;
      transition: background 0.15s ease, border-color 0.15s ease;
      user-select: none;
    }

    .factor-item:hover, .factor-item.active {
      background: #f1f5f9;
      border-color: #cbd5e1;
    }

    .biotic-column .factor-item.active {
      background: #f0fdf4;
      border-color: #86efac;
    }

    .abiotic-column .factor-item.active {
      background: #f0f9ff;
      border-color: #7dd3fc;
    }

    .factor-icon {
      font-size: 18px;
      line-height: 1;
      display: flex;
      align-items: center;
      justify-content: center;
      width: 24px;
      height: 24px;
    }

    .factor-name {
      font-size: 13px;
      font-weight: 600;
      color: #334155;
    }

    .factor-tag {
      margin-left: auto;
      font-size: 11px;
      font-weight: 500;
      color: #94a3b8;
    }
  </style>
</head>
<body>

  <div class="header-bar">
    <div class="main-title">Ecosystem Components</div>
    <div class="filter-group">
      <button class="filter-btn active" onclick="setFilter('all')">All</button>
      <button class="filter-btn" onclick="setFilter('biotic')">Biotic</button>
      <button class="filter-btn" onclick="setFilter('abiotic')">Abiotic</button>
    </div>
  </div>

  <div class="columns-grid">
    
    <div class="column-card biotic-column" id="cardBiotic">
      <div class="badge-header biotic-badge">
        <span>🌱</span> Biotic Factors
      </div>
      <div class="items-list">
        <div class="factor-item" onclick="toggleItem(this)">
          <span class="factor-icon">🦌</span>
          <span class="factor-name">Deer</span>
          <span class="factor-tag">Living</span>
        </div>
        <div class="factor-item" onclick="toggleItem(this)">
          <span class="factor-icon">🌳</span>
          <span class="factor-name">Oak Tree</span>
          <span class="factor-tag">Living</span>
        </div>
        <div class="factor-item" onclick="toggleItem(this)">
          <span class="factor-icon">🍄</span>
          <span class="factor-name">Fungi</span>
          <span class="factor-tag">Living</span>
        </div>
        <div class="factor-item" onclick="toggleItem(this)">
          <span class="factor-icon">🧫</span>
          <span class="factor-name">Bacteria</span>
          <span class="factor-tag">Living</span>
        </div>
        <div class="factor-item" onclick="toggleItem(this)">
          <span class="factor-icon">🍂</span>
          <span class="factor-name">Fallen Leaf</span>
          <span class="factor-tag">Once-Living</span>
        </div>
      </div>
    </div>

    
    <div class="column-card abiotic-column" id="cardAbiotic">
      <div class="badge-header abiotic-badge">
        <span>☀️</span> Abiotic Factors
      </div>
      <div class="items-list">
        <div class="factor-item" onclick="toggleItem(this)">
          <span class="factor-icon">☀️</span>
          <span class="factor-name">Sunlight</span>
          <span class="factor-tag">Light</span>
        </div>
        <div class="factor-item" onclick="toggleItem(this)">
          <span class="factor-icon">🌡️</span>
          <span class="factor-name">Temperature</span>
          <span class="factor-tag">Heat</span>
        </div>
        <div class="factor-item" onclick="toggleItem(this)">
          <span class="factor-icon">💧</span>
          <span class="factor-name">Water</span>
          <span class="factor-tag">Moisture</span>
        </div>
        <div class="factor-item" onclick="toggleItem(this)">
          <span class="factor-icon">🪨</span>
          <span class="factor-name">Soil & Rocks</span>
          <span class="factor-tag">Minerals</span>
        </div>
        <div class="factor-item" onclick="toggleItem(this)">
          <span class="factor-icon">💨</span>
          <span class="factor-name">Wind & Air</span>
          <span class="factor-tag">Gases</span>
        </div>
      </div>
    </div>
  </div>

  <script>
    function setFilter(type) {
      document.querySelectorAll('.filter-btn').forEach(btn => {
        btn.classList.remove('active');
        if (btn.textContent.toLowerCase() === type) {
          btn.classList.add('active');
        }
      });

      const biotic = document.getElementById('cardBiotic');
      const abiotic = document.getElementById('cardAbiotic');

      if (type === 'biotic') {
        biotic.classList.remove('dimmed');
        abiotic.classList.add('dimmed');
      } else if (type === 'abiotic') {
        biotic.classList.add('dimmed');
        abiotic.classList.remove('dimmed');
      } else {
        biotic.classList.remove('dimmed');
        abiotic.classList.remove('dimmed');
      }
    }

    function toggleItem(el) {
      el.classList.toggle('active');
    }
  </script>
</body>
</html>

OGS.8.LS.7

Aligned learning resources

Related diagrams